1. Field of the Invention
The present invention relates to a manifold for dilation catheters used in coronary angioplasty.
2. Description of the Prior Art
Percutaneous transluminal coronary angioplasty is a procedure for dilating coronary arteries which are partially occluded or blocked. A special catheter which carries an inflatable dilation balloon at the distal end is employed to reshape a partially occluded artery. The balloon is inserted in a deflated condition in the restricted portion of the artery and inflated by filling with a pressurized radioopaque fluid. In this way, the occluded lumen is reshaped by the dilation balloon to allow better passage of blood. The obstructing material is neither dislocated nor removed from the vessel, but rather pressed against the wall. The wall, in turn, is stretched to accommodate the previously obstructing material. After the lumen has been reshaped, the dilation balloon is deflated and removed. The site of the formed obstruction is examined and, if necessary, the procedure is repeated until the obstructed segment remains open.
The technique is more fully explained in the Gruntzig et al. U.S. Pat. No. 4,195,637. The Gruntzig Patent shows conventional tube connections at the proximal end of a catheter. One connection is to a pressure measuring device with a suction-pressure pump. The same lumen is also connected to a roller pump through a second connector. The Gruntzig method incorporates a guide catheter within a dilating catheter having a double lumen support or carrier tube.
The Sampson U.S. Pat. Nos. 4,582,181 and 4,641,654 disclose low profile dilation catheters and integral guide wires for steering the catheters into an artery system. The steerable balloon dilation catheter assemblies disclosed have dye injection and pressure measurement capabilities associated with the guide wire lumen. At the proximal end of the catheter, a first fitting is coupled to the balloon lumen and a second fitting is in communication with the guide wire lumen. The relative sizes of the guide wire lumen and the guide wire are such that dye injections and/or pressure measurements may be performed through the second fitting. Sampson also discloses a compressive O-ring seal at the proximal end of the second fitting which seals about the guide wire. A guide wire rotation facilitating device is coupled to the guide wire at the proximal end.
The Packard et al. U.S. Pat. No. 4,646,742 discloses an angioplasty catheter having a hub on the proximal end of the catheter body to facilitate the manipulation of a distally located valve and useful for introduction of a perfusant along the length of the catheter body.
The Daniels et al. U.S. Pat. No. 4,655,746 discloses a catheter device for transferring fluid material to or from a selected-length segment of vessel. The device includes a pair of inflatable balloon catheters. The catheter includes a two-armed manifold connected to a flanged end of a tube. A guide wire is lead through an O-ring seal to a wheel mounting for rotating the guide wire. The two-armed manifold in turn leads to a second two-armed manifold which in turn leads to a three-armed manifold.
The Frisbie et al. U.S. Pat. No. 4,664,133 discloses a steerable dilation catheter assembly having an adapter with at least one arm. The proximal end of a guide wire extends through the adapter. A rotation limiting device is secured to the proximal end of the guide wire and an O-ring seal may be tightened by a thumb screw of the rotation limiting device.
WO 86/06285 discloses a balloon angioplasty system with a microdilation probe which can be passed through the main lumen of the dilation catheter.
The above described patents provide compressive seals at the proximal end of the guide wire or guide catheter. An alternative to a compressive seal is an elastic diaphragm. Elastic diaphragms may be punctured by the physician or purchased pre-punctured. For example, United States Catheter Corp. (a division of C.R. Bard, Inc.), Billerica, Mass., sells elastic diaphragm containing Y-type adapters (see Catalog Nos. 006055, 006056 and 006057). To a large extent, the choice of a compressive seal or a diaphragm seal is a matter of personal preference to the physician performing the angioplasty procedure.
One problem with compressive seals is the potential for separation of the compressive nut, also known as a hemostatic valve nut, from the valve unit. Another problem is undesired rotation of the hemostatic valve nut during the angioplasty procedure. Such undesired rotation can result in an alteration of the resistive force of the seal on the guide wire, as the guide wire is pushed into the patient to create the path to the stenosis.